glDrawElements needs an IBO when using a core profile. The particle
system's IBO is actually quite static since it's always a triangle
strip with 2 triangles followed by a PRI. Therefore, this reduces the
amount of data we have to send to the GPU compared to the previous
solution.
Also, remove the workaround when glPrimitiveRestartIndex is not
available since it is always available with OpenGL 3.1 and when using
a core profile we are guaranteed to have OpenGL 3.1 anyway.
The former is not available in a OpenGL 3 core profile, but glGenerateMipmap
is available since OpenGL 3.0, and so is always available when we have a
core profile.
glObjectLabel would result in invalid VBOs if called on a not-instantiated object. glGenBuffers does apparently only reserve the name and not create the buffer itself.
For me the landscape and some objects were drawn completely black.
More information: http://stackoverflow.com/questions/26614130/opengl-debug-extension-with-globjectlabel
Found via --debug-opengl
which lead to
gl: high severity API error: GL_INVALID_VALUE error generated. ObjectLabel: unknown buffer object <name>
This reverts commit 790219ac7e.
This commit broke support for Mac OS X since Apple only supports OpenGL 3.0
with a core profile, not a compatibility profile. Revert this commit
temporarily for the 7.0 release, until we port all OpenGL usage to the core
profile with 8.0.
This fixes#1495.
This would crash for me when starting a game in developer's mode. Not sure if this is the best place for the fix. Maybe there is some other underlying issue. ck?
In doing so, refactor the way C4FoWDrawStrategy works slightly. Get rid of
immediate mode OpenGL, and instead populate a vertex array and an index array
as vertices are added to the draw strategy. Then render everything as
triangles.
The actual rendering is then performed in C4DrawStrategy::End(). It passes
the accumulated vertices to the GL. Also get rid of the notion of multiple
passes in C4DrawStrategy. Instead, C4DrawStrategy::End() can simply just draw
the bunch of vertices multiple times. This allows us to do the vertex
generation and GPU upload only once, instead of repeating it for every pass.
This allows the strategy to keep some state between invocations. I want to
use this in order to store a VBO in the draw strategy, and to avoid having
to re-create the VBO for every rendering.
We are already using VBOs for meshes, so we can rely on them being available.
VBOs are shared between contexts, so #1195 is not an issue, either. However,
keep the workaround in place for the VAO, which is not shared between
contexts.
Replace the hardcoded VAI_ constants with that. The VAI constants are now
moved to C4DrawGL as C4SSA_ constants, similar to the C4SSU ones. This allows
to introduce other attributes to replace vertex positions, normals, colors
and texture coordinates with attributes in later commits. This, in turn, is
needed because the built-in attributes are no longer available in the OpenGL
core profile.
Also, while at it, cleanup C4Shader a bit. Use std::vector<> instead of
maintaining an own array of uniform names. Delete the vertex and fragment
objects after the full shader program has been linked. Make sure that
C4Shader::Init keeps the old program in place if the new one cannot be
compiled or linked.
Surfaces are initially created in locked state, and only when unlocked the
memory buffer with the surface data is uploaded to the GPU. The FoW code
however never unlocks the surface but instead operates on the OpenGL texture
directly. To fix this, introduce a new flag for C4Surface to create it in an
unlocked state.
This is not a memory leak in the traditional sense as a pointer to the buffer
is still available and is being freed when the surface is being destructed
at the end of the game. However, during the game there might be several
megabytes allocated that are never used.
I'm not really sold by this Lock/Unlock mechanism. Instead, there should
simply be a function to obtain the current texture data, and a function to
upload new texture data. That's for another time though...
Code outside of C4FoWRegion should not care about the internals of the
class. Therefore, we remove direct access to the backing surface (and
secondary buffer surface) and replace it instead with accessors that
return those few values that are required by outside code.
In a surprising touch, using shaders to affect pretty much every pixel
that gets drawn on screen means there is little reason for code to ask
the renderer if it knows about shaders.
There are only a couple of error values worth considering, so we can just
write out own function for it. Disable error checking in C4FoWRegion.cpp as
well, since we have the --debug-opengl flag now.
This should allow us to get rid of the GLU dependency soon.
Otherwise, when starting the next scenario, random spots would be initially
re-lighted. That's not necessarily a problem, but unnecessary work, and it
triggered the assertion in C4FowAmbient::UpdateFromLandscape if the relight
was scheduled for a region that's outside of the landscape boundaries of the
second scenario.
Instead, compute the projection, modelview and normal matrices explictly
and upload them as shader uniforms. This is one step towards using the
OpenGL 3 core profile.
Maikel de Vries